Yeah, my rucksack items keep on disapearing then reappearing and often on market days i'll have to go into my rucksack to show somethng to Van to sell because it won't just come up in the normal selling view.
I've also been fishing an had my fishing pole disapear off the screen so that it just looks like i'm standing there doing nothing. I've lost alot of fish like that because i'll press the X button to recast and just end up pulling up my rod!